Influence of part-to-part gaps in air distribution system on operation of DTH hammer

The authors illustrate the role of pneumatic percussive machines in drilling. The article presents the elementary diagram of down-the-hole (DTH) hammer with the marked places of air leakages in the system of air distribution and describes and their influence based on the research data. The variation in the basic power characteristics of the machine is given as function of the size of gaps in the sliding joints. It is shown that the machine design can be improved by means of using elastic valve to allow discharge of air working chambers during the idle stroke of the hammer.